System of electrical distribution.



PATENTED MAY 5, 1908. A. S. HUBBARD.

SYSTEM OI" ELECTRICAL DISTRIBUTION.

APPLICATIONk FILED AUG.10,1905.

/TNESSES/ /NVE/VTOH UNITED sTATEs PATENT oEEIcE.

ALBERT S. HUBBARD. OF BELLEVILLE, NEW JERSEY, ASSIGNOR TO GOULD STORAGE BATTERY COMPANY, CORPORATION OF NEW YORK.

SYSTEM OF ELECTRICAL DISTRIBUTION.

Specification of Letters Patent.

Patented May 5, 1908.

Application led August 10, 1905.v Serial No. 278,622.

To all ywhom it may concern:

Be it known that LALBERT S. Hussain), a citizen of the United States, and a resident of Belleville, Essex county, State of New Jersey, have invented certain new and useful Improvements in Systems of Electrical Distribution, of which the following is a speci iication.

My invention relates to systems of elec trical distribution in which an auxiliary storage battery is connected in parallel to compound wound main generators in order that that battery may maintain a substantially constant load on the main generator. My invention comprises a novel means for regulating the action of thebattery.

I refer to apply my invention to systems emp oying a booster 1n series with the battery so that the battery charge and discharge YVthe E. M. F.

`booster itself is very may be regulated by varying the booster voltage. By my invention I regulate the strength of the booster. lield and therefore with variations in the difference of potential across tlie series iields of the compound wound main generators. This I do by connecting a regulating coil, preferably the field coil of an exciter, in shunt to the series iield winding of the compound vwound main generator, if there be only one, and I provide means whereby fiuctuations of current in this regulating coil due to changes in the difference ofvpotential across the series win ing will regulate the booster voltage. If there be several compound wound generators I may, ifeq'ualizing connections be provided, connect the coil so that it is in shunt with all of the series windings, but lI prefer to employ separate regulating coils one connected across each of the series windings, the regulation then being dependent upon the average of the changes in the different regulating coils.

' In order to utilize the feeble currentst'hat would necessarily be obtained from coils connected across the series field coils of the dynamo I have provideda s ecial arrangement of apparatus whereby c langes 1n these coils may indirectly affect' the booster armature in such a way that the effect upon the `largely magnified. This magnifying apparatus includes an extremely small exciter whose fields are ,controlled by of the booster in accordance the coils in shunt to the series fields of the main' generators and which 1n yturn excites another regulating dynamo, which, in the present instance, isa counter machine, being connected in series with the field winding of the booster in a circuit across the main circuit so that the voltage of the counter machine and the voltage of the main line act oppositely upon the booster field and therefore upon the booster field strength.

This magnifying apparatus is of value` wherever 1t is desirab e that the booster shall be regulated by initial changes of very small amount. K,

The drawing `accompanying this speciiication is a diagram disclosing one embodiment of my invention.

In this embodiment A A are the armatures of two main generators. A A are the series field coils for these generators and A2 A2 are the shunt field coils thereof.

1, 1- represent the two 'circuits of the individual generators, while 2, 2, represent the combined generator circuit.

E is the storage battery and B the booster armature, the two being connected in series4 in the circuit 3, which is connected in parallel to the Generator circuit 2 with reference to the woinng circuit 4.

B is the ield coil of the booster, which is connected in series with the armature yD of a counter electro-motive-force` machine in a circuit across the conductors 2, 2. The direction and strength of the current in the field-winding B (and conse ently the direction and value of the E. F. generated by B) depend upon the relation between the potential difference across 2.-2 and that across D. l

M is a motor which is mechanically coni nected to the booster and drives it unless the system is so adjusted that. at times the booster is generating an E. M. F. in opposition to that of the current liowing through it, in which case the booster would become a motor and the machine M would deliver current to the circuit 4. The armature D is driven through its mechanical connectionr with B and M when its E. M. F. is greater than the lpotential difference across 2 2, but is itself a driver when its E. M. F. becomes less than the otential difference across 2-2.

T e potential difference across 22 is constant, or nearly so, so that the strength of the booster field and, therefore, the E. M. F. of the booster armature will be dependent upon the E. M. F. generated by'l), being at its maximum in one direction when the E. M. F. of D is lowest and being at its maximum in the other direction when the E. M. F. of D is highest. The E. M. F. of D is directly proportional to the strength of the current in D1 which represents the field winding of the counter machine. This fieldv winding receives its current from the armature C of an exciter which is mechanically connected to a motor M to run at substantially constant speed.-

, The strength of the current furnished by the exciter will depend upon the strength of its field winding. This consists of two field lcoils C1. Each of these field coils is connected in shunt to one of the series field coils A of the compound wound generators. The strength of the current in either of these coils is directly dependent upon the potential difference at its terminals and this in turn is directly de endent u'pon the strength of the current in the corresponding coil A?. It will be seen, therefore, that the booster armature will varyits E. M. F from a maximum in one direction to a maximum in the other direction to vary the charge and discharge of the battery, in direct accordance with the variation of potential difference across coils A between whatever limits the apparatus may be adjusted for. Very slight differences in the potential difference across these main-'series coils will l be very much magnified in affecting the E. M. F. of the booster.

I have provided a separate motor M to drive the armature C, because this armature may be made very small relatively to the armature D, while the latter is small relatively to the armature B. It will, therefore, l be found convenient to place the machines C l and Ml close to the generators, or perhaps on a bracket on a switchboard, connecting them to the outfit D B M only by a single pair of light conductors.

In operation it is preferable to adjust the system so that for a given current in the main generators the voltage of the booster will be zero, and the boosters will float across the line neither charging nor discharging, and for a given percentage of increase in the generator current, causing a like increase iii the drop of potential across the series coils A', the booster will reach its maximum voltage in one direction, while for a similar decrease of generator current the booster will reach its maximum voltage in the other direction causing the maximum charge of the batteries.

I do not desire to be limited to the particular arrangement of apparatus shown and described, since such a paratus might be i varied considerably wlii e still maintaining i the regulation of the booster by coils acted upon by the varying drop of potential on the main'generator coils A', and acting upon the booster through intermediate magnifying i a paratus. I would particularly point out t at while I prefer to connect the coils C across the terminals of the coils A, thus utilizing the entire drop of potential of the latter coils, yet it is not essential that this entire dro i of potential should b e utilized.

aving thus described my invention, what I claim as new, and desire to protect by lietters Patent, is:

1. The combination of a pound-wound generators in parallel, a circuit in arallel therewith containing a batter an a booster armature in series with each other, and a plurality of reful'ating coils for said booster each connecte in shunt to the series-windings of one of said generators.

2. The combination with a compoundwound main generator, a battery in parallel therewith, and a booster in series with the battery, of a field-winding for said booster, a dynamo in series with said field-windiiig, an exciter for said dynamo, and a regulating coil fory said exciter connected across the series field coil of the main generator.

3. A compound-wound generator, a circuit in arallel therewith containing a battery an a booster armature in series therewith, a dynamo connected to the booster field, a field coil for said dynamo, an exciter for said field coil, means for op osing the action of said dynamo, and a regu ating coil for the exciter connected across the series field-coil of the main generator.

4. A compound-wound generator, a circuit in dparallel therewith containing a battery an a booster armature in series therewith, a d 'namo connected to the booster field, a field coil for said dynamo, an exciter for said field coil, a regulating coil for the exciter connected across the series field-coil of the main generator, and means for opposing the reguating effect of said regulating coil upon the booster field.

5. A main generator, a circuit in arallel ltherewith containin a battery and a Ooster armature in series terewith, a dynamo connected to the booster field, a field coil for said dynamo, an exciter for said field coil, means for automatically regulating said exciter, a motor mechanically connected to the booster and to the dynamo connected to the booster field, and a separate motor mechanically connected to the. exciter.

6. A conipound-wound generator, a circuit in arallel therewith containing a battery an a booster armature in series therewith, a dynamo connected to the booster field, a

plurality of' comfield coil for said dynamo, an exciter for said field coil, a regulating coil for the exciter connected across the series coil of the main enerator, a motor mechanically connecte to the booster and to the dynamo connected to the booster field, and a separate motor me'- chanically connected to the exciter.

7. The combination of a main genera/tor,

auxiliary battery and a booster in series therewith, of a booster iield exciting dynamo, an automatically regulated exciting dynamo therefor, a motor mechanically connected to the booster and the former exciting dynamo, and an independent motor connected to the latter exciting dynamo.

8. The combination with a main generator, a regulating battery and a booster in the battery circuit of a air of regulating dynamos, one having a fie d winding connected to be influenced by changes of electrical condition of the s stem and its armature connected to the fiel Winding of the other regulating dynamo to govern the current therein, whi e the latter dynamo is connected to the booster ieldwinding to govern the current therein.

9. The combination With a main generator, a regulating battery and a booster in the battery circuit of a air of regulating dynamos, one having a fie d windin@r connected to be influenced by changes of electrical condition of the system and its armature connected to the field winding of the other regulating dynamo to govern the current therein, while the latter dynamo is a counter electro-motiveforce machine connected in series with the booster field winding in a branch circuit.

10. The combination with a main generator, a regulating battery and a booster in the battery circuit, of a pair of regulating dynanios, one having a field winding in the branch circuit of the main generator and its armature connected to the iield winding of the other regulatingidynanio to govern the current therein, while the latter dynamo is connected tothe booster iield winding to govern the current therein.

In testimony whereof, l have signed my name to this specification, in the presence of two subscribing witnesses.

ALBERT S. HUBBARD.

Witnesses:

RICHARD Eran, DE FOREST JETMORE. 

